using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.ObjectPool;

namespace ObjectPoolDemo
{
    public class Startup
    {
        // This method gets called by the runtime. Use this method to add services to the container.
        // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddRazorPages();

            // 1. add service DefaultObjectPoolProvider. 
            // The maximum number of objects to retain in pool is "Environment.ProcessorCount * 2"
            services.TryAddSingleton<ObjectPoolProvider, DefaultObjectPoolProvider>();
            // 2. add service to create ObjectPool<Connection>.
            services.TryAddSingleton(options =>
            {
                var provider = options.GetRequiredService<ObjectPoolProvider>();
                var policy = new ConnectionPooledObjectPolicy();
                return provider.Create(policy);
            });

        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseRouting();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapRazorPages();
            });
        }
    }
}
